DESCRIPTION: This application proposes to test the hypothesis that young children (10 years of age) with gestational exposure to the environmental toxicants found in Lake Ontario fish (e.g., PCBs, mercury, cadmium) will exhibit exaggerated responses to acute stress. Preliminary evidence suggests that a) newborns with highest gestational exposure to contaminants found in Lake Ontario fish have significantly poorer habituation recoveries and appear to overreact to stimulation, and b) at 6 months, 4 years, and 6 years of age these children show emotional dysregulation. Emotional dysregulation is frequently associated with corresponding increases in cardiovascular and cortisol reactivity to acute stress, however, psychophysiological reactivity has not yet been investigated in humans with gestational exposure to environmental toxicants. Determining the effects of these environmental toxicants on psychophysiological reactivity to acute stress is important given evidence that a) heightened or prolonged cardiovascular reactivity is associated with pathophysiological processes (e.g., vascular changes, lipid mobilization), and b) heightened cortisol reactivity is associated with psychopathological processes (e.g., social withdrawal, anxiety). The proposed study examines reactivity to acute stress in children currently participating in the Oswego Newborn and Infant Development Project, an ongoing longitudinal study of 224 children born to women interviewed between 1991 and 1994. Extensive data currently exists for these children, including background sociodemographic characteristics (e.g., socioeconomic status, maternal health behaviors) and gestational toxicant exposure levels determined by maternal dietary recall and cord blood levels. The proposed laboratory protocol will provide a) assessment of emotional, cardiovascular, and cortisol reactivity to mildly stressful events, and b) assessment of a number of psychosocial variables (e.g., anxiety, depression). Important features of this proposed study include a) the participation of children currently involved in a longitudinal study and, therefore, no new recruitment, b) an assessment of a full range of possible consequences of gestational exposure to environmental toxicants, including emotional, cardiovascular, and cortisol reactivity, and c) the ability to relate these emotional and psychophysiological outcomes to the large set of existing data for these children (e.g., cognitive functioning).